A new series of
1-ethyl-6-fluoro-7-piperazinyl-4-oxo-3-(substitutedarylidinylcarboxy-hydrazido)quinolines
3-7 and
1-ethyl-6-fluoro-7-piperazinyl-4-oxo-3-(2¢-substitutedaryl-4¢-oxo-1¢,3¢-thiazolidin-3¢-yl)aminocarboxyquinolines 8-12
have been synthesized in order to determine their antimicrobial activities and
feasible structure-activity relationships. The synthesized compounds and
reference drugs have been tested in vitro
against various strains of bacteria: E. coli ATCC 25922, B. subtilis ATCC
1633 and S. aureus ATCC 25923 and the fungi: C. albicans ATCC
2091, A. niger
ATCC 9029 and C. krusei ATCC 6258. Microbiological results showed
that the synthesized compounds possessed a broad spectrum of antimicrobial
activity against the microorganisms tested. 1-Ethyl-6-fluoro-7-piperazinyl-4-oxo-3-[2¢-(o-methoxyphneyl)-4¢-oxo-1¢,3¢-thiazolidin-3¢-yl)aminocarboxyquinoline
10 has displayed more potent
antibacterial activity as compared to standard drug, chloroamphenicol and rest
of the compounds of this series. This compound has also exhibited significant
antifungal activities, which is not more than that of fluconazole. The
structural assignments of newly synthesized compounds are based on IR, 1H
NMR, mass spectral studies and elemental analysis.